Such a system as follows is widely utilized today: the operator of a website published on the Internet makes a contract with an advertisement agent that runs an advertisement intermediary service and posts an advertisement for an enterprise distributed by the advertisement intermediary service on the webpage. And a referral fee is paid to the website operator based on the number of times the advertisement is displayed on viewers' Web browsers or viewers select a link in the advertisement to move to a corresponding webpage of the enterprise, or the number of times viewers select the advertisement to move to a corresponding page that sells the enterprise's products and buy such products and/or the amount of purchase.
For instance, AdSense (Non-Patent Document 1) of Google (a registered trademark) solicits Web operators to post advertisements on their webpages. Google has a Web operator post an advertisement on his webpage and pays a referral fee to the Web operator when a viewer of the webpage clicks a link in the advertisement.
A conventional mechanism for posting an advertisement on a website is conceptually illustrated in FIG. 11. When a webpage request 211 is made to a website 201 from a Web browser 102, the website 201 provides an advertisement attached webpage 212. Here, the website 201 typically transmits HTML containing a URL indicating the location at which advertisement information resources are stored, and upon receiving the HTML, the Web browser makes an advertisement information request 213 to ask for resources from the URL of the advertisement information resources. When advertisement information 214 is returned, the Web browser displays advertisement information. Advertisement information is typically rendered using an image and/or animation for catching viewers' attention. Such an images or animation is designed as a link so that a page containing more detailed information (typically a webpage of the enterprise posting the advertisement) can be returned when a viewer selects the advertisement.
In the link, introducer identification information is embedded. When a viewer of the webpage selects the advertisement on a web browser, a notice of advertisement selection 215 is sent to the advertisement intermediary service 202. Upon receiving the request, the advertisement intermediary service 202 redirects the viewer to the website of the enterprise 106 that corresponds to the advertisement and displays a page corresponding to the advertisement on the web browser 102. Here, the advertisement intermediary service 202 counts the number of times the advertisement is selected for each piece of introducer identification information or the like by utilizing the introducer information embedded in the link of the advertisement. Based on the result of counting, the advertisement agent determines an amount to pay as a referral fee.
The invention according to Patent Document 1 describes a method for the purchaser of a product to select a party to which a referral fee is paid such as when one buys a product through an affiliate advertisement.
The invention according to Patent Document 2 describes a method for embedding a web browser in a portion of an application having a GUI and displaying an advertisement on the browser. By doing so, the invention realizes such control as to enable utilization of functions of the application only while the advertisement is displayed, for example.    Patent Document 1: Japanese Patent Laid-Open Publication No. 2007-18200    Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-323571    Non-patent Document 1: Google AdSense https://www.google.com/adsense/login/ja/index.html